National Oceanic and Atmospheric Administration National Weather Service United States Department of Commerce
Current conditions at

St. Louis Downtown Airport (KCPS)

Lat: 38.56°NLon: 90.15°WElev: 410ft.

Fair

55°F

13°C

Humidity 90%
Wind Speed Calm
Barometer 29.99 in (1015.5 mb)
Dewpoint 52°F (11°C)
Visibility 10.00 mi
Last update 10 Oct 11:53 pm CDT
Extended Forecast for

O'Fallon IL

  • Tonight

    Tonight: Partly cloudy, with a low around 53. Light northeast wind.

    Low: 53 °F

    Partly Cloudy

  • Sunday

    Sunday: Sunny, with a high near 88. Light and variable wind.

    High: 88 °F

    Sunny

  • Sunday Night

    Sunday Night: Increasing clouds, with a low around 65. Light and variable wind becoming south around 5 mph in the evening.

    Low: 65 °F

    Increasing
    Clouds

  • Columbus Day

    Columbus Day: Sunny, with a high near 94. Southwest wind 6 to 13 mph.

    High: 94 °F

    Sunny

  • Monday Night

    Monday Night: Clear, with a low around 68. South wind 7 to 10 mph.

    Low: 68 °F

    Clear

  • Tuesday

    Tuesday: Sunny, with a high near 92.

    High: 92 °F

    Sunny

  • Tuesday Night

    Tuesday Night: A 30 percent chance of showers after 1am. Mostly clear, with a low around 69.

    Low: 69 °F

    Mostly Clear
    then Chance
    Showers

  • Wednesday

    Wednesday: Showers likely and possibly a thunderstorm. Partly sunny, with a high near 85. Chance of precipitation is 70%.

    High: 85 °F

    Showers
    Likely

  • Wednesday Night

    Wednesday Night: Showers likely. Mostly cloudy, with a low around 64. Chance of precipitation is 60%.

    Low: 64 °F

    Showers
    Likely

Detailed Forecast

Tonight
Partly cloudy, with a low around 53. Light northeast wind.
Sunday
Sunny, with a high near 88. Light and variable wind.
Sunday Night
Increasing clouds, with a low around 65. Light and variable wind becoming south around 5 mph in the evening.
Columbus Day
Sunny, with a high near 94. Southwest wind 6 to 13 mph.
Monday Night
Clear, with a low around 68. South wind 7 to 10 mph.
Tuesday
Sunny, with a high near 92.
Tuesday Night
A 30 percent chance of showers after 1am. Mostly clear, with a low around 69.
Wednesday
Showers likely and possibly a thunderstorm. Partly sunny, with a high near 85. Chance of precipitation is 70%.
Wednesday Night
Showers likely. Mostly cloudy, with a low around 64. Chance of precipitation is 60%.
Thursday
Showers likely, with thunderstorms also possible after 1pm. Mostly cloudy, with a high near 79. Chance of precipitation is 60%.
Thursday Night
A 30 percent chance of showers and thunderstorms. Mostly cloudy, with a low around 57.
Friday
A 20 percent chance of showers. Partly sunny, with a high near 71.
Friday Night
Partly cloudy, with a low around 46.
Saturday
Sunny, with a high near 64.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
O'Fallon IL
 38.59°N 89.89°W (Elev. 541 ft)
Last Update:
10:26 pm CDT Oct 10, 2026
Forecast Valid:
11pm CDT Oct 10, 2026-6pm CDT Oct 17, 2026
 
Forecast Discussion
 
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Additional Resources

Radar & Satellite Image

Link to Local Radar Data Link to Satellite Data

Hourly Weather Forecast

National Digital Forecast Database

National Digital Forecast Database Maximum Temperature Forecast

High Temperature

National Digital Forecast Database Weather Element Forecast

Chance of Precipitation